Pfizer received a Complete Response Letter from the FDA on 4/23/18 highlighting the need for additional technical information. Though this is a setback for Pfizer's Herceptin biosimilar program, there is no reason to believe that Pfizer won't be able to address the FDA's concerns and get the development program back on track.
In addition to its Herceptin (trastuzumab) biosimilar, Pfizer has five other biosimilars in phase 3 development.
A Forbes article https://www.forbes.com/sites/greatspeculations/2017/07/03/why-investment... pointed out that the combined sales of these products was $35 Billion in 2014. If the entire sales were replaced with biosimilars, even at a 50% discount, this would open up a market worth almost $18 billion to Pfizer.
Pfizer has already demonstrated that it has the expertise to develop biosimilars. It launched a biosimilar to Remicade (Inflectra) and received approval for another in-house developed version of Remicade (IXIFI). Though Pfizer has said that it does not intend to market IXIFI in the US. Inflectra generated $135 million in 4Q17.
Overall, Pfizer has 13 biosimilars in various phases of development.